Portable fan



FIG. 1 is a front elevation view of a portable fan showing the new design;

FIG. 2 is a back elevation view thereof;

FIG. 3 is a left-side view thereof;

FIG. 4 is a right-side view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a perspective view thereof;

FIG. 8 is a perspective view thereof; and,

FIG. 9 is a perspective view of the portable fan in an unfolded position thereof.

The broken lines depict portions of the portable fan article that form no part of the claimed design. 

CLAIM The ornamental design for a portable fan, as shown and described. 